[sdiy] Jim Dunlop Cry Baby Wah-Wah.. 500mH inductor replacement with an inductor simulator circuit.. Feasable ?? follow up..

[Paul Perry]

This may be heresy, but replacing the original inductor by a toroidal wound
one would prevent picking up external fields.
There are also ferrite pot cores (that's pot as in shaped like a pot) if
you feel experimental.

paul perry Melbourne Australia

On Sat, Jun 15, 2024 at 5:18 AM Tom Wiltshire <tom at electricdruid.net> wrote:

> Yes, exactly!
>
> Tom
>
>
> On 14 Jun 2024, at 19:29, Jean-Pierre Desrochers <jpdesroc at oricom.ca>
> wrote:
>
> This schematic is a later generation… with input buffering :
>
> <image001.png>
>
> *De :* Tom Wiltshire <tom at electricdruid.net>
> *Envoyé :* 14 juin 2024 13:52
> *À :* Jean-Pierre Desrochers <jpdesroc at oricom.ca>
> *Cc :* synth-diy at synth-diy.org
> *Objet :* Re: [sdiy] Jim Dunlop Cry Baby Wah-Wah.. 500mH inductor
> replacement with an inductor simulator circuit.. Feasable ?? follow up..
>
> Ok, so it's clear that yours is one of the original old-school Crybabies.
> Nice.
>
> It may not sort out your current issue, but you should really try putting
> a buffer between the guitar and the wah. At the moment, that input
> transistor with its low impedance is hanging off your input signal and
> killing the treble, even when the wah is switched out of circuit (the
> switch only switches the output). That will affect the whole rest of the
> pedal chain.
>
>
> On 14 Jun 2024, at 15:54, Jean-Pierre Desrochers via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> To answer some questions :
>
> *….. With so many power sources, you may be hearing a ground loop.  Never
> assume that the common return of multiple power sources are all the same
> potential.*
> There are no ground loops in my pedal board. Unselecting the Wha makes the
> 60hz hum completely go away.
> And placing the inductor in a specific way in the Wha metal box almost
> kill completely the hum.. so no ground loop for sure.
>
> *….. I'd start by looking at some of the *other* pedals to see how many
> could be converted to standard 9V centre-negative, and then reduce the
> number of transformers to reduce the noise.*
> > 4 of these pedals are powered with there separate AC supplies (9VAC,
> 9VAC, 7.5VAC & 22VAC).
> > The other pedals are powered using 9VDC standard BOSS supplies
>
>
> *The 4 x AC powered pedals :*
> *2 x LINE6 modelers that could be run using 6VDC supplies (they can run on
> 4 x 1.5vdc C cells) eliminating two transformers..*
> *1 x Blackstar DS2 powered by 16VAC (no possible DC powering):*
> *<image001.png>*
> *1 x Electro Harmonix Hum Debugger pedal powered by 7.5VAC (no schematic
> available)*
>
> The following pictures shows the real actual schematic of my Wha.
> It’s an Italian Jen Cry Baby with a FASEL branded inductor.
> The bottom picture shows what I’ve done to ‘place’ the inductor at the
> ‘sweet spot’ to get the less hum possible. Not bad..
> But a shielded inductor could be fine (but expensives..)
>
> And again, this is not a ground loop problem..
>
> <image004.jpg>
>
>
>
>
>
>
> On Jun 13, 2024, at 4:46 PM, Jean-Pierre Desrochers wrote:
> > I have a guitar pedal board that uses 8 pedals.
> > The first pedal (receiving the guitar) is a Jim Dunlop Cry Baby Wah-Wah.
> > The following pedal is a switchable  overdrive with high gain.
> > Then the pedal chain goes on with 6 other pedals to a final tuner that
> drives a guitar amplifier. Ok.
> > 4 of these pedals are powered with there separate AC supplies (9VAC,
> 9VAC, 7.5VAC & 22VAC).
> > The other pedals are powered using 9VDC standard BOSS supplies.
> > Here is my problem :
> > Since the Wah-Wah is connected at the ‘head’ of the pedal chain and uses
> an internal 500mH inductor in its circuit
> > it acts like the secondary of a transformer picking up 60Hz
> > from all the nearby transformers of the board.
> > I had to unsolder the inductor from the inside PCB and,
> > using short lenghts of wires connected to it … place it in the Wah-Wah
> housing
> > at a ‘specific’ place and angle to get the less 60Hz pickup.
> > This is annoying..
> > Now I can play with a little back ground hum when the Wah-Wah is
> activated..
> > I  was wondering if I could use an active inductor simulator circuit
> > In place of the 500mH passive inductor.. (??)
> > Feasable ??
>
>
>
>
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